'Overwhelmed' troops shot at refugees who were protesting against plans to be sent home, official says.

Congolese security forces have killed at least 18 Burundian refugees during clashes over plans to send some of them home.

Josue Boji, a Democratic Republic of Congo interior ministry official, said troops had tried to disperse the refugees by "firing in the air but were overwhelmed" when the group responded by throwing stones in Friday's confrontation.

Police and soldiers opened fire as the refugees protested over the resettlement plan and tried to free some of their arrested compatriots in the town of Kamanyola in eastern DRC, sources told the Reuters news agency.

Activist Wendo Joel said the refugees had seized a weapon and killed a soldier, though that account was not confirmed by other sources.

"The soldiers first fired in the air but there were many refugees," Joel told the Reuters news agency. "I have counted 32 bodies. There are also about 100 wounded."

MWC News was unable to independently verify the death toll.

A Western diplomat said at least 18 refugees died and dozens more were wounded.

A local army spokesman, Dieudonne Kasereka, told Reuters there had been clashes between soldiers and refugees armed with knives and machetes, but that he did not know if there were any deaths.

More than 400,000 refugees have fled Congo's neighbour Burundi since violence erupted there in April 2015 when President Pierre Nkurunziza said he would seek a third term in office, a move his opponents said was unconstitutional